Sanitary napkin



Feb. 20, 1951 c. L. R. DE WET 2,542,909

SANITARY NAPKIN Filed Aug. 23, 1949 SL/ 7 TER D@ YEQS ggf Patented Feb. 20, 1951 UNITED STATES PATENT OFFICE SANITARY NAPKIN Charl Louis Roux de Wet, Neenah, Wis., assignor to International Cellucotton Products Company, Chicago, Ill., a corporation of Delaware Application August 23, 1949, Serial No. 111,953

6 Claims. l

The present invention relates to catamenial bandages or sanitary napkins and is of particu- `lar value for mitigating odors produced by the body excretions absorbed by such bandages, whether such odors are initially present in the secretions or are subsequently develo-ped.

Various attempts have been made to mitigate the odors which sometimes develop incident to the use of catamenial bandages. Reference may be had to the prior U. S. patents to Cline, No. 2,024,145, issued December 17, 1935, and to Williams, No. 2,067,961, issued January 19, 1937. Also, various types of deodorizing agents have been employed for the purpose indicated, for example, metallic peroxides such as zinc peroxide, the use of which is suggested in the patent to Melton, No. 2,144,632. However, the efficiency oi such known methods and materials has not been entirely satisfactory in certain cases.

One of the most effective of the known methods of deodorizing sanitary napkins includes the incorporation of zinc peroxide into the napkin. The deodorizing effect of zinc peroxide appears to be due, in part, to the liberation of oxygen by reason of the chemical reaction which takes place between the zinc peroxide and the liquid body excretion. Notwithstanding the widespread use of zinc peroxide as a deodorant for the purpose, its use under certain conditions causes the development of an odor which is different than the original odor of the exudate but which is bjectionable to some persons. Furthermore, relatively large amounts of zinc peroxide are required to produce a noticeable reduction in odor, and the inclusion of large amounts of the zinc peroxide, a substantially insoluble compound, reduces the absorptivity of the pad and thereby impairs its efficiency.

I have found that, although the liberation of oxygen may be of considerable value in removing odors and in preventing odors from developing, the e'iciency, i. e. the percentage of cases where the development of odors is prevented or mitigated, may be greatly increased by the addition to a napkin of one or more Quaternary ammonium compounds in combination with a relatively small amount of zinc peroxide. The Quaternary ammonium compounds have many important properties which enhance their effectiveness in a sanitary napkin, e. g. they are colorless and odorless, and in the concentrations employed are non-toxic and non-irritating. Moreover, these Quaternary compounds serve to soften the fibers of the napkin and are not readily leached away from the zone in which they are needed during use. Certain of the Quaternary ammonium compounds by themselves may be employed in combination with a cellulosic carrier to eiect deodorization of liquid body excretions as described in my co-pending application Serial No. 105,901 which was filed on July 20, 1949.

In the event that certain of the Quaternary ammonium compounds are employed by them selves in mitigating odors from body excretions, there is a reactio-n between the odorless Quaternary ammonium compound and the body excretion which produces, under some conditions, an aromatic odor which has been found objectionable by some persons. When the zinc peroxide and the Quaternary ammonium compound are introduced into the napkin together, the oombined action of the two materials is effective to eliminate substantially all traces of odor, and this deodorizing action is effective over a prolonged period of time.

Among the Quaternary ammonium compounds which have been successfully used in combination with zinc peroxide and by the use of which extremely high deodorizing efliciency is obtained are the following: l

where n is at least 2;

4. Di-isobutyl phenoxy-ethoxy-ethyl di-methyl benzyl ammonium chloride, which compound may be prepared in a manner similar to that set forth in connection with compound 2 above;

5. Lauryl pyridinium chloride.

My investigations have shown that a sanitary napkin or catamenial bandage should, for proper deodorization, have incorporated therein at least l5 mg. (milligrams) of commercial zinc peroxide (50 per cent active zinc peroxide and 50 per cent zinc oxide) and from 1.5 to 30 mg. of the Quaternary ammonium compound. This material desirably should be incorporated into an active portion of the napkin, i. e. a portion of the napkin through which the excretion will pass. Extensive tests have shown that a napkin, for example, containing 20 mg. commercial Zincperoxide and 6 mg. of a quaternary ammonium compound (0.026 gram of the mixture) is as effective in mitigating odors-asrfrom aboutn Ito grams of commercial., zinc peroxide alone'` Thus; it will be seen that on a comparative weight basis, my improved deodorant is from about 40 to 200 timesl as eiective as zinc peroxide. Further, a sam'.- tary napkin which contains my improvedY composition completely deodorizesthe exudateand there are no new odors formed in the..sanitary` napkin as a result of the deodorization` of the excretions. In other words, the napkinis odor.- less before, during, and after use;

The preferred proportions of zinc peroxide and, the quaternary ammonium compound per napkin arefromabout 20,-40A mg; of. commercial. zinc per- Y oxide and tofrom about. 6 to` 15mg. of. the quae' ternary' ammoniumv compounds, All` of! the*Y quae ternaryM ammoniumv compoundsV will produce a marked deodor-izing eiectwhen` combinedwith. Zinc peroxide, however, those.- compoundslwhich havebeen set forth above have produced extreme- 1yj eiective -deodorization efliciencies.

Specificy Example,

InY the drawingY accompanying this application,

Fig. l isi ai diagrammatic viewY showing the equipment andf process usedffor producing ade.-l odorizing stripr for.` incorporation in a sanitary, napkin; andconstructed in accordance with my invention; and

Fig. 2i is: ax. perspective view Lshowing a. catame-, nial bandage equipped-with one of my improved deodorizing strips.

In the drawing, Fig. l, a supply rolll Iof suit'- able permeablemateriali. is shown in positionv to be impregnatediwith-a deodorant compositionin accordance withA the invention. In the present instanceth'e permeable materiali's paper'lwadding or tissue of a type similar to that" which isusedv for. facial tissuesfor` for the; plies of absorbentY Wadding. The sheet employed.- has ai dryer-basis weight of about 8-1bs-. tothe-ream of 3,000squarev feet; Wit-hfa` creping; ratio of between 11.5fand2.0, althoughilighter. or heavier sheets` with diierent ratios ofi-creping; may bev employed, Yif needed, t'ofsuitother conditions;

The` web. of untreated creped` waddingi passes over idler rolls I2 and I3 to the nip oi-fa pair of coating: rolls.. comprising an applicator roll |43. preferablyV provided" with, a soft rubber exterior, and a drying and creping roll I5". The: applicator roll I4 is positioned so its lower surface is wettedby. theliquid I5 containedin a. suitable trough. I .1. The Vliquid is rapidly circulated through the trough I'I'by means of a pump, ISand suitable pipingy connections` I9- and 20. Ther supply,y of; treatngfliquid: I5. in the troughV I'I ist-maintained by: feeding; into the troughadditional liquid throughaliquidasupplylline2,I-.

Said liquid I6 comprises a liquid dispersionrof a suitable adhesive andcontainsirr suspension or: solution the active ingredients of thedeodorizing materiali The adhesive is a water dispersion of Io'oiledorY gelatinizedn starch but` other adhesives be used; AV relatively small. amount. oi ad-A hesive, is required.. Good results have beenobf. tained. by using. a good. grade. of, cooked,VV soluble. starch. inoan. amount. representing7 about 5%. ot

4 the dry Weight of the total solids used in the formula.

To insure a proper dispersion or suspension it may be advisable to use a small percentage of a dispersing agent. In such cases, I have successfully used .4% (based upon the dry weight of the total solids) of sodium hexametaphosphate. typica'lgformula for the V-slurry` Ywhich .contains the deodorizing. substances isY the following;

Commercial Zinc peroxide (containing of the pure chemical and 50% of zinc Thus,itmay be seen that the. slurry contains, Y

onthe dry basis, ahou't25 per cent-ot; commercial zinc peroxide, about Bfper Cent-of boric acid; and about 8 perv centof the-.pure Quaternary ammonium compound. This means that. inV the slurry there. are about` 25 partsbyweightfof commer cial zinc peroxidetoabout S'partsby weight of.Y boric acid andA about 8 parts by weight ofthe pure, quaternary ammonium. compound.

rIihe use of boricvacid'appearsto be ofradvan'- tage;r inincreasing the acidity of; the body eX- cretion. to afpHotaboutd to 7.5; reduces theetendency of.v theexcretiontol irritate the skin. Insteadof bor-ic acid,.Imay use other. wealracids,l such as citric. or tartaric, such acidic salts, as mono-ammonium phosphate; ammoniumVV sulphate or zinc sulphatevor. salts such-A as ammonium; di-basic phosphate which` becomes acidic upon heating. According to mypresentl information, it is not advisable to userelatively stronger orfmore reactive acids-which, whenincorporated with-theother ingredients, appear tof produce premature orfundesirable reactions.

The clay actsY as anadsorbent; The purposey oftheother ingredients has already been de scribed. Insomey cases, the adhesive, cla-y,xan df Weak acidmay be omitted..

Suioient': pressure is applied to the rubber faced applicator roll' I4, and the consistency or;v Vamount of.- water in theliquid dispersion is suitably adjusted; so-that the proper'amountv of ma.- terial is applied tothe web II when, it passes' -Y throughthe nip ofY the. coating rolls. I4 and I5.

For the purpose indicated1tlie; slurry may-corr.,

venientlyfhave a consistency; ofabout. 25- per cent,

centage of the water of thedispersion. Enough` water is driven oil to-bring thesheet into proper condition.v of. dryness toy bel removed and- Creped: by the` usualcreping doctor 22; From thecrep-A ing4 doctor 22,` the treatedsheet passesk under an idler 11011.23. and around a set. of. driers, for examplethreedriers 2&25 and 26, whichA complete, thedrying of the sheet tov a moisture content of normal paper dryness, i. e. containing about 5% of. moisture. If the sheetisof substantial` width,k itmay thenbe slit into .strips of the proper width by, means.` of. a slitting mechanism4 indicated. at

21 from which it passes to a re-winding arrangement indicated generally at 28.

When the strip is to be used for deodorizing sanitary napkins of the usual construction, it will preferably have been cut to a width slightly less than the width of the fibrous, absorbent, liquid permeable element of the sanitary napkin, and such strip is made up in lengths long enough to cover an area equal to the zone of contact between the napkin and the person of the wearer.

For example, a strip may conveniently be about 5 inches long and slightly less than 3 inches wide. If a single strip is to be employed in a sanitary napkin, the operation is adjusted so that the strip will contain say 20 mg. of commercial zinc peroxide and 6 mg. of di-isobutyl-cresoxy ethoxy dimethyl benzyl ammonium chloride.

The deodorizing strip 29 is incorporated to the absorbent element 30 of the napkin which is equipped with the usual gauze wrapper 3| the folds of which are shown folded b-ack to expose the interior construction. Said strip may be employed on either side of the element 30, as shown at 29 or 29', or it may be incorporated in the center of the pad as shown at 29".

Tests which have been carried out to ascertain the deodorizing effect of sanitary napkins which have been made in accordance with the foregoing specific example have shown that the deodorizing effect in the napkin is equivalent to the deodorizing effect obtained when about 21/2 grams of commercial zinc peroxide is incorporated in a napkin. Thus, it will be seen that on a weight basis, the deodorizing composition in accordance with the specific example is 100 times as effective as an equivalent weight of zinc peroxide. The element containing the combination of the zinc peroxide and the quaternary ammonium compound is soft and pliable and has substantially all of its original absorptivity.

The slurry employed in applying the mixture of zinc peroxide and quaternary ammonium compound to the deodorizing strip has been found to be stable in water so that there is little danger that the activity of the mixture will be reduced by circulating the slurry through the 6 about 1.5 to 30.0 milligrams of a quaternary ammonium compound and over about 15 milligrams of commercial zinc peroxide.

2. A sanitary napkin which includes a brous, liquid permeable, absorbent element and a deodorant distributed throughout the active portion thereof, the said deodorant comprising from about 1.5 to 30.0 milligrams of a quaternary ammonium compound and from about 20 to 40 milligrams of commercial zinc peroxide.

3. A sanitary napkin which includes a brous, liquid permeable, absorbent element and a deodorant distributed throughout the active portion thereof, the said deodorant comprising from about 6 to 15 milligrams of a quaternary ammonium compound and from about 20 to 40 milligrams of commercial zinc peroxide.

4. A sanitary napkin which includes a fibrous, liquid permeable, absorbent element and a deodorant distributed through the active portion thereof, the said deodorant comprising from 1.5 to 30.0 milligrams of di-isobutyl cresoxy ethoxy ethyl dimethyl benzyl ammonium chloride and from about 20 to 40 milligrams of commercial zinc peroxide.

5. A sanitary napkin which includes a brous, liquid permeable, absorbent element and a deodorant distributed throughout the active portion thereof, the said deodorant comprising from about 1.5 to 30.0 milligrams of di-isobutyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride and from about 20 to 40 milligrams of commercial zinc peroxide.

6. A sanitary napkin which includes a fibrous, liquid permeable, absorbent element and a deodorant distributed throughout the active portion thereof, the said deodorant comprising from about 1.5 to 30.0 milligrams of alkyl dimethyl benzyl ammonium chloride, said alkyl group containing from 8 to 18 carbon atoms and from about 20 to 40 milligrams of commercial zinc peroxide.

CHARL LOUIS ROUX DE WET.

REFERECES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,950,286 Barkow Mar. 6, 1934 1,953,526 Ainsley et al Apr. 3, 1934 2,024,145 Cline Dec. 17, 1935 2,131,235 Randall et al Sept.. 27, 1938 OTHER REFERENCES Annals of Surgery, Oct. 1943, page 744. Drug and Cosmetic Industry, Nov. 1943, page 585. 

1. A SANITARY NAPKIN WHICH INCLUDES A FIBROUS, LIQUID PERMEABLE, ABSORBENT ELEMENT AND A DEODORANT DISTRIBUTED THROUGHOUT THE ACTIVE PORTION THEREOF, THE SAID DEODORANT COMPRISING FROM ABOUT 1.5 T 30.0 MILLIGRAMS OF A QUATERNARY AMMONIUM COMPOUND AND OVER ABOUT 15 MILLIGRAMS OF COMMERCIAL ZINC PEROXIDE. 